JP2020053554A - Hermetic sealing cap and manufacturing method thereof - Google Patents

Abstract

To provide a hermetic sealing cap having a flange portion, in which outflow of solder to a region other than a joining region is suppressed.SOLUTION: In a hermetic sealing cap used for an electronic component housing package including an electronic component housing member for housing an electronic component, a surface of a substrate that includes a cavity portion having a cavity constituted by a bottom plate portion and a side plate portion, and a flange portion that is annularly provided so as to surround an opening of the cavity is covered with a Ni layer. A bonding region to be bonded to the electronic component housing member is provided on the flange portion of the cap, and a solder portion made of Au-Sn-based solder is provided in the bonding region. The Ni layer is exposed in a region other than the bonding region of the cap.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a hermetic sealing cap and a method for manufacturing the same.

  2. Description of the Related Art An electronic component housing package (hereinafter, simply referred to as a package) in which an electronic component is housed is known from Patent Document 1 and the like. Such a package includes a ceramic member and a metal cap. A housing space for housing the electronic component is formed between the ceramic member and the cap. The electronic component is mounted on the ceramic member and housed between the ceramic member and the cap. The ceramic member and the cap are joined by soldering on the joining surface. The inside of the package is hermetically sealed by joining a ceramic member and a cap.

JP 2017-120865 A

  The hermetic sealing of the package with the ceramic member and the cap utilizes the wettability of the melted solder (liquid solder). The cap and the ceramic member are joined through an upstream process performed by the cap manufacturer and a downstream process performed by the package manufacturer.

  The upstream step is a step of forming a solder portion in the joining region of the cap. An adhesion layer made of a metal such as Au having a high wettability with respect to the liquid solder is formed in a joining region of the cap. The solder portion is formed on the surface of the adhesion layer by using an annular square solid solder component (also called a solder ring or a solder washer). Specifically, the solid solder component is introduced into a continuous furnace or a batch furnace in a state where the solid solder component is arranged on the surface of the adhesion layer corresponding to the joining region of the cap, and heated to re-melt the solid solder component (reflow) To make a liquid solder. At this time, since the surface of the adhesion layer has high wettability with respect to the liquid solder, the liquid solder spreads to the joining region of the cap. Thereafter, when the cap is cooled and the liquid solder is re-solidified, a solder portion is formed in the joining region of the cap. In most cases, components of the adhesion layer such as Au dissolve together with the solid solder and are taken into the solder portion.

  The downstream step is a step of manufacturing a package by joining the cap and the ceramic member. A metallized layer having enhanced wettability with respect to liquid solder is formed in the joining region of the ceramic member. The solder part of the cap and the metallized layer of the ceramic member are brought into contact with each other and introduced into a continuous furnace or a batch furnace and heated while performing vacuum degassing to re-melt the solder part to form a liquid solder. At this time, since the surface of the metallized layer has high wettability with respect to the liquid solder, the liquid solder spreads to the joining region of the ceramic member. Thereafter, when the package is cooled and the liquid solder is re-solidified, a solder portion is formed again between the joining region of the cap and the joining region of the ceramic member. By such a process, the cap and the ceramic member can be joined to each other, and the inside of the package can be hermetically sealed.

  By the way, when the solder portion is re-melted in the downstream process, if the solder provided in the joining area flows out to an unintended area, an appropriate hermetic sealing state cannot be obtained, and the internal electronic components cannot be removed. May be damaged. In particular, in a package provided with a cap having a flange portion proposed in Patent Literature 1, it is required to make the flange portion as small as possible in order to meet the recent demand for miniaturization of the package. It is difficult to prevent outflow of solder.

  Therefore, an object of the present invention is to provide a hermetic sealing cap having a flange portion, in which the outflow of solder to a region other than the joining region is suppressed, and a method of manufacturing the same.

The hermetic sealing cap according to one aspect of the present invention,
An airtight sealing cap used for an electronic component housing package including an electronic component housing member for housing an electronic component,
A surface of a substrate having a cavity portion having a cavity formed by a bottom plate portion and a side plate portion, and a flange portion provided in an annular shape so as to surround an opening of the cavity, is covered with a Ni layer,
A joining area for joining to the electronic component housing member is provided in the flange portion,
A solder portion made of Au-Sn based solder is provided in the joining region so as to cover the Ni layer,
A hermetic sealing cap in which the Ni layer is exposed in a region excluding the bonding region.

A method for manufacturing a hermetic sealing cap according to one aspect of the present invention,
A method for manufacturing a hermetic sealing cap used for an electronic component housing package including an electronic component housing member for housing an electronic component,
The hermetic sealing cap,
A surface of a substrate having a cavity portion having a cavity formed by a bottom plate portion and a side plate portion, and a flange portion provided in an annular shape so as to surround an opening of the cavity, is covered with a Ni layer,
A joining area for joining to the electronic component housing member is provided in the flange portion,
A solder portion made of Au-Sn based solder is provided in the joining region so as to cover the Ni layer,
The Ni layer is exposed in a region excluding the bonding region,
The manufacturing method comprises:
Pressing a metal plate to form an intermediate body including the cavity portion and the flange portion,
A Ni layer forming step of forming the Ni layer on the entire surface of the intermediate;
Forming an Au layer on the entire surface of the Ni layer,
A solder portion forming step of forming the solder portion made of Au-Sn based solder on the surface of the Au layer corresponding to the joining region of the flange portion;
An etching step of removing the Au layer by an etching process.

  According to the present invention, there is provided a hermetic sealing cap having a flange portion, in which the outflow of solder to a region other than the joining region is suppressed, and a method for manufacturing the same.

FIG. 2 is a perspective view of an electronic component housing package including the hermetic sealing cap according to the embodiment. It is sectional drawing of a package. FIG. 3 is an enlarged view of a part III in FIG. 2. It is a modification of the cap which concerns on this embodiment, Comprising: It is a figure corresponding to the enlarged view of the III section of FIG. It is a figure showing the press process of the manufacturing method of the cap concerning this embodiment. It is a figure showing the Ni layer formation process of the manufacturing method of the cap concerning this embodiment. It is a figure showing the Au layer process of the manufacturing method of the cap concerning this embodiment. It is a figure showing the solder fusion process of the manufacturing method of the cap concerning this embodiment. It is a figure showing the solder solidification process of the manufacturing method of the cap concerning this embodiment. It is a figure showing an etching process of a manufacturing method of a cap concerning this embodiment. It is a figure which shows the oxide layer formation process of the manufacturing method of the modification of the cap which concerns on this embodiment. It is a SEM photograph of a cap of a comparative example. It is a SEM photograph of a cap of an example. It is a SEM photograph of a cap of a comparative example. It is a SEM photograph of a cap of an example.

  Hereinafter, an example of an embodiment of a hermetic sealing cap according to the present invention will be described with reference to the drawings. It should be noted that the present invention is not limited to these exemplifications, but is indicated by the claims, and is intended to include all modifications within the meaning and scope equivalent to the claims.

  FIG. 1 is a perspective view schematically illustrating an electronic component housing package 1 (hereinafter simply referred to as a package 1) including a hermetic sealing cap 10 (hereinafter simply referred to as a cap 10) according to the present embodiment. As shown in FIG. 1, a package 1 includes a ceramic ceramic member 2 serving as an electronic component housing member for mounting and housing an electronic component 3 and a ceramic member 2 for hermetically sealing the electronic component 3. And a metal cap 10 to be joined. The electronic component 3 is mounted on the ceramic member 2, and the electronic component 3 is accommodated in an accommodation space formed by the ceramic member 2 and the cap 10.

  The metal cap 10 has a metal plate having a mechanical strength suitable for a structural material, such as an Fe-Ni-based alloy, an Fe-Ni-Co-based alloy, an Fe-Cr-based alloy, or an Fe-Ni-Cr-based alloy. Can be formed by using a metal plate made of the Fe-based alloy described above. The cap 10 naturally has a mechanical strength suitable for a structural material, but preferably has a thermal expansion coefficient similar to that of the ceramic member 2 to be joined.

  Therefore, the metal plate used for the cap 10 is, for example, an Fe-Ni-based alloy containing 10 to 48% by mass of Ni, or a Fe-Ni-Co-based alloy containing 10 to 45% by mass of Ni and 10 to 25% by mass of Co. Alloy, Fe-Cr-based alloy containing 2 to 20% by mass of Cr, Fe-42% by mass Ni-6% by mass Cr-based alloy containing 35 to 50% by mass of Ni, Fe-42% by mass Ni-4 % Cr-based alloy, Fe-47% by mass Ni-6% by mass Cr-based alloy, or the like.

For example, the thermal expansion coefficient of the ceramic member 2 is 6.9 to 7.5 × 10 ⁻⁶ / ° C. (room temperature −400 ° C.). The thermal expansion coefficient of Fe-29Ni-17Co is 4.6 to 5.2 × 10 ⁻⁶ / ° C (room temperature-400 ° C). The thermal expansion coefficient of Fe-36Ni is 1.8 to 2.2 × 10 ⁻⁶ / ° C. (room temperature −100 ° C.). The thermal expansion coefficient of Fe-42Ni is 4.5 to 5.3 × 10 ⁻⁶ / ° C. (room temperature −320 ° C.). The thermal expansion coefficient of Fe-42Ni-6Cr is 9.5 to 10.1 x ^10-6 / C (room temperature-400C). The cap 10 may be made of a metal material having a thermal expansion coefficient close to that of the ceramic member 2 to be joined (preferably 0.2 to 2 times, more preferably 0.5 to 1 times the ceramic member 2). it can. Note that the room temperature may be, for example, 20 ° C. or more and 40 ° C. or less.

  FIG. 2 is a cross-sectional view schematically illustrating the package 1. As shown in FIG. 2, the cap 10 has a base material 20 having a cavity 21 and a flange 22. The substrate 20 is made of a metal. The cavity 21 has a bottom plate 23 and a side plate 24. A cavity C formed by the bottom plate portion 23 and the side plate portion 24 is formed. In FIG. 2, the cavity C is open downward.

  The bottom plate 23 has a flat plate shape. The side plate portion 24 is provided in an annular square shape at the edge of the bottom plate portion 23, and extends substantially vertically downward from the bottom plate portion 23. The side plate portion 24 may extend with an outward taper so that the cavity C opens more.

  The flange portion 22 is provided annularly so as to surround the opening of the cavity C. An annular joining region A for joining to the ceramic member 2 is set in the flange portion 22. The flange portion 22 extends substantially parallel to the direction away from the cavity C along the bottom plate portion 23 from the tip of the side plate portion 24. A joining region A is set on the lower surface (on the front surface) of the flange portion 22 (see FIG. 3). In FIG. 2, the joining region A is illustrated in the flange portion 22 for clarifying the joining region A. The annular joining area A 'of the ceramic member 2 corresponding to the annular joining area A of the cap 10 is shown in FIG. The joining area A and the joining area A 'may have substantially the same shape.

  FIG. 3 is an enlarged view of a part III in FIG. FIG. 3 is an enlarged schematic view of the flange portion 22. As shown in FIG. 3, the surface of the base material 20 having the cavity portion 21 and the flange portion 22 is covered with the Ni layer 26. The joining region A is set on the surface including the center of the lower surface of the flange portion 22. In the joining region A, a solder portion 25 made of Au-Sn based solder is provided in a region including the center of the joining region A so as to cover the Ni layer 26. At least in the region other than the bonding region A, the Ni layer 26 is exposed. The solder portion 25 may be configured to cover the entire Ni layer 26 in the bonding region A, or may be configured to cover a portion of the Ni layer 26 in the bonding region A as shown in FIG. Good.

  The Ni layer 26 is a protective layer provided to suppress the corrosion of the metal forming the base material 20 even in a high-temperature and high-humidity environment due to its corrosion resistance, and to maintain the hermetic sealing in the package 1. Further, the Ni layer 26 also has a function as an adhesion layer that adheres the base material 20 and the Au layer 31 (see FIG. 7). The Ni layer 26 preferably has a thickness of about 0.5 to 5.0 μm.

  The Ni layer 26 can be composed of pure Ni, a Ni-based alloy, or the like. The Ni layer 26 is, for example, a Ni-P-based alloy containing 1 to 30% by mass of P, a Ni-Cu-based alloy, a Ni-Cr-based alloy, a Ni-Mo-based alloy, etc. And a Ni-based alloy containing Ni.

  According to the cap 10 according to the present embodiment, the Ni layer 26 is exposed in a region other than the bonding region A. Unlike the surface made of Au, the surface made of Ni has low wettability to the Au-Sn liquid solder. For this reason, when the manufacturer of the package 1 remelts the solder portion 25 in the downstream process, it is difficult for the Au-Sn-based liquid solder to flow outward from the bonding region A.

  Au-Sn-based liquid solder has a smaller contact angle and is more easily wetted on a hydrophilic surface such as an Au-plated surface as the roughness becomes larger, and a larger roughness on a hydrophobic surface such as a Ni-plated surface or an oxidized surface. The contact angle increases, making it difficult to wet. Therefore, it is convenient to express the wettability of the surface with respect to the Au-Sn liquid solder by surface roughness, and it is particularly practical to express the wettability by the maximum height (Rz) specified in JIS B0601. Therefore, by setting the maximum height of the surface of the Ni layer of the cap to 1.0 μm or more, the wettability of the surface of the Ni layer with respect to the Au—Sn-based liquid solder is further reduced, and the liquid solder is moved outward from the bonding region A. It is preferable to enhance the effect of suppressing the flow of water.

  The maximum height (Rz) of the surface of the Ni layer of the cap is at least 1.0 μm, preferably at least 1.2 μm, more preferably at least 1.2 μm, from the viewpoint of reducing the wettability of the surface of the Ni layer with respect to the Au—Sn-based liquid solder. Is 1.4 μm or more. Further, the maximum height (Rz) of the surface of the Ni layer of the cap is desirably 3.0 μm or less from the viewpoint of practical use such as manufacturing efficiency, and desirably 2.5 μm or less from the viewpoint of further improving practicability. .

  In the present embodiment, as in the modification shown in FIG. 4, preferably, a region adjacent to the inner peripheral edge of the solder portion 25 in the annular bonding region A (the right edge of the bonding region A in FIG. 4) is provided. , A first oxidized region 27 in which the Ni layer 26 is oxidized is provided in a ring shape. Further, preferably, in a region adjacent to the outer peripheral edge of the solder portion 25 in the annular joining region A (the left edge of the joining region A in FIG. 4), a second dioxide region 28 in which the Ni layer 26 is oxidized is provided in an annular shape. Have been. In the modified example shown in FIG. 4, a solder portion 25, a first oxidized region 27, and a second dioxide region 28 are provided in a region adjacent to the joint region A.

  The first oxidized region 27 and the second dioxide region 28 in which Ni has been oxidized have lower wettability with respect to the Au-Sn-based liquid solder than the surface of Ni. Therefore, when the first oxidation region 27 and the second oxidation region 28 are provided in a ring shape, the Au-Sn-based liquid solder flows out of the bonding region A to the outside when the solder portion 25 is remelted in the downstream process. It becomes difficult. If the width of the first oxidized region 27 and the second dioxide region 28 provided in an annular shape is small and insufficient, the Au-Sn-based liquid solder gets over the first oxidized region 27 and the second dioxide region 28 and joins. It may flow out of the area A to the outside.

  Next, a method for manufacturing the cap 10 according to the present embodiment will be described with reference to FIGS. Further, a method of manufacturing a cap (hereinafter referred to as a cap 10 for simplicity) according to a modified example of the present embodiment (see FIG. 4) will be described with reference to FIG. 5 to 11, only the periphery of the flange portion 22 is schematically shown.

(Pressing process)
First, a metal plate having a predetermined thickness is subjected to press working such as bending, drawing, and punching to form an intermediate body having a cavity and a flange. The intermediate corresponds to the base member 20 including the cavity portion 21 and the flange portion 22 shown in FIG. If necessary, the intermediate is subjected to processing such as deburring and washing to obtain the substrate 20.

(Ni layer forming step)
Next, as shown in FIG. 6, a Ni layer 26 is formed on the entire surface of the substrate 20. The Ni layer 26 can be formed by a plating process such as electrolytic plating or electroless plating. Alternatively, the Ni layer 26 can also be formed by vapor deposition such as physical vapor deposition (PVD: Physical Vapor Deposition) or chemical vapor deposition (CVD: Chemical Vapor Deposition). Among them, the Ni layer 26 is preferably formed by electrolytic plating (Watts bath, wood bath, etc.). It is preferable that the thickness of the Ni layer 26 be about 0.5 to 5.0 μm.

(Au layer forming step)
Further, as shown in FIG. 7, an Au layer 31 is formed on the entire surface of the Ni layer 26. The Au layer 31 can be formed by a plating process such as electrolytic plating or electroless plating. Alternatively, the Au layer 31 can be formed by vapor deposition such as physical vapor deposition (PVD) or chemical vapor deposition (CVD). Among these, the Au layer 31 is preferably formed by electrolytic plating.

  The Au layer 31 is preferably formed of pure Au having high wettability with respect to the Au-Sn liquid solder. The thickness of the Au layer 31 is preferably about 0.01 to 0.50 μm. When the surface of the Au layer 31 having such a thickness is subjected to surface element analysis by SEM-EDX, the Au (element) may be analyzed as 5% to 25% by mass. In addition, SEM means scanning electron microscope (Scanning Electron Microscope), and EDX means energy dispersive X-ray analysis (Energy Dispersive X-ray spectrometry).

(Solder forming process)
Next, a solder portion 25 made of Au-Sn based solder is formed in the joint region A. The step of forming the solder portion 25 includes a solder melting step shown in FIG. 8 and a solder solidification step shown in FIG.

(Soldering process)
First, as shown in FIG. 8, an annular rectangular solder member 40 made of Au—Sn-based solder is placed on the surface of the Au layer 31 corresponding to the position where the solder portion 25 is provided in the joint area A. The shape and dimensions of the solder member 40 may be determined by the possibility that the solder member 40 melts into liquid solder and flows out of the joining region A to the outside, or the solder formed when the liquid solder solidifies again. It is preferable to set in consideration of the shape and size of the portion 25.

  The substrate 20 on which the solder member 40 is placed is placed in a furnace, and the solder member 40 is melted. The temperature inside the furnace is preferably set to about 280 ° C. to 320 ° C. which is suitable for melting the Au—Sn based solder under a nitrogen gas or hydrogen gas atmosphere. Since the surface of the Au layer 31 has high wettability with respect to the Au-Sn-based liquid solder, the Au-Sn-based liquid solder spreads to the bonding region A.

(Solder solidification process)
When the Au-Sn liquid solder spreads to the bonding region A and is cooled to about room temperature, the Au-Sn liquid solder solidifies. As a result, as shown in FIG. 9, a solder portion 25 made of Au-Sn based solder is formed in the joint region A. Here, when the solder member 40 shown in FIG. 8 is melted, Au of the Au layer 31 that has been in contact with the solder member 40 is taken into the solder portion 25 as shown in FIG. Therefore, the solder portion 25 is provided so as to cover the Ni layer 26 as if it were formed directly on the surface of the Ni layer 26.

(Etching process)
Next, the Au layer 31 is removed by performing an etching process on the base material 20, and the Ni layer 26 is exposed as shown in FIG. In the etching process, the Au layer 31 is removed by using an etching solution that easily dissolves Au and hardly dissolves Sn. As such an etching solution, for example, a solution obtained by adding an appropriate amount of potassium cyanide to Gold Stripper Concentrate T manufactured by Nippon Electroplating Engineers Co., Ltd. can be used.

  From the viewpoint of enhancing the wettability to the Au—Sn-based liquid solder, the surface of the Ni layer 26 that is exposed by removing the Au layer 31 is Au in the energy dispersive X-ray analysis (EDX). Is preferably not more than 0.1% by mass and Ni is not less than 90% by mass, and the maximum height (Rz) is preferably not less than 1.0 μm as described above. The surface of the Ni layer 26 can be obtained by adjusting various conditions of the etching process, for example, the type of the etching solution, the concentration of the etching solution, the temperature of the etching solution, the etching time, and the like.

(Oxide layer forming step)
After the etching step, as shown in a modification shown in FIG. 11, a region adjacent to the inner peripheral edge of the solder portion 25 in the annular joint region A is irradiated with a laser beam to thereby oxidize the Ni layer 26. The oxidized region 27 may be formed in a ring shape. Similarly, by irradiating a laser beam to a region adjacent to the outer peripheral edge of the solder portion 25 in the annular joint region A, the second dioxide region 28 in which the Ni layer 26 is oxidized may be formed in a circular shape. As the laser light, for example, a laser light using YVO ₄ (Yttrium Vanadium tera oxide) as a medium can be used. The width of the first oxidized region 27 and the second oxidized region 28 can be approximately 30 μm to 60 μm. In addition, due to the first oxide region 27 and the second dioxide region 28 having sufficiently large widths, when the solder portion 25 is re-melted, the Au-Sn-based liquid solder gets over the first oxide region 27 and the second dioxide region 28. It is easy to prevent the outflow to the outside of the joining region A.

  Such an oxide layer forming step is preferably performed after the Au layer forming step and before the solder portion forming step. FIG. 11 shows a case where the first oxidation region 27 and the second oxidation region 28 are formed on the base material 20 after the Au layer forming step and before the solder part 25 forming step. As shown in FIG. 11, the surface of the base material 20 in this state is covered with the Au layer 31 except for the solder part 25. When the surface of the Au layer 31 is irradiated with a laser beam in this state, the laser beam evaporates the Au layer 31 to expose the Ni layer 26 under the Au layer 31, and the surface of the Ni layer 26 is further heated by the heat of the laser beam. Oxidize. As a result, a first oxide region 27 and a second dioxide region 28 in which the surface of the Ni layer 26 is oxidized are formed in the region irradiated with the laser beam.

  By forming the first oxidized region 27 and the second dioxide region 28 after the Au layer forming process and before the solder portion forming process in this manner, during the solder melting process of the solder portion forming process, the first oxidized region 27 and the second oxide region 27 move outward from the joining region A. Au-Sn-based liquid solder is less likely to flow out. Further, as described above, when the cap 10 and the ceramic member 2 are joined in the downstream step, the liquid solder does not easily flow out of the joining area A due to the first oxidation area 27 and the second oxidation area 28.

  The oxide layer forming step may be performed after the solder part forming step. By forming the first oxidation region 27 and the second oxidation region 28 before performing the downstream process, as described above, when the cap 10 and the ceramic member 2 are joined in the downstream process, 27 and the second dioxide region 28 make it difficult for the liquid solder to flow outward from the joint region A.

  Next, the caps of the examples according to the present invention (samples Nos. 6 to 11) and the caps of comparative examples different from the present invention (samples Nos. 1 to 5) were prepared and evaluated. In each of the samples, the base material was a base material made of an Fe-based alloy formed of a metal plate made of an Fe-Ni-Co-based alloy containing 30% by mass of Ni, and the Ni layer was formed by electrolytic Ni plating. The Ni plating layer was used, and the Au layer was an Au plating layer formed by electrolytic Au plating.

  Table 1 shows the sample Nos. The result of performing a surface elemental analysis by SEM-EDX on an arbitrary point in a region other than the bonding region A (see FIG. 3) of the caps 1 to 11 is shown. For surface element analysis, EDX (model Emax xact) manufactured by HORIBA, Ltd. attached to SEM (model S-3400N) manufactured by Hitachi High-Technologies Corporation was used. Various conditions of the SEM and EDX were set to an acceleration voltage of 15 kV, a working distance of 10 mm, a measurement time of 50 sec, and a collection coefficient rate of 2 to 4 kp. The units of the numerical values shown in Table 1 are mass%. "No detection" in Table 1 means 0.1% by mass or less, which is below the detection limit of the device.

(Comparative example)
Sample No. 1 to 5 are caps of comparative examples. Sample No. Nos. 1 to 5 form a Ni layer on the entire surface of the base material, form an Au layer on the entire surface of the Ni layer, form a solder portion in the joint region A, and then perform a cap without etching step. It is. Therefore, of the entire surface of the cap, the surface other than the solder portion provided in the joint region A is an Au layer. Sample No. In Tables 1 to 5, when a surface elemental analysis was performed on a region other than the bonding region A, as shown in Table 1, more than 0.1% of Au was detected in about 6% to 8.5%. In SEM-EDX, Ni contained in the Ni layer underlying the Au layer was detected in a range of less than 90%, and Fe contained in the base material underlying the Ni layer was detected in a range of less than 5%.

(Example)
Sample No. Reference numerals 6 to 11 denote caps according to the embodiment of the present invention. Sample No. 6 to 11 are caps on which a Ni layer is formed on the entire surface of the base material, an Au layer is formed on the entire surface of the Ni layer, a solder portion is formed in the joint region A, and thereafter, an etching process is performed. is there. Therefore, of the entire surface of the cap, the surface other than the solder portion provided in the joining region A is not covered with the Au layer, and the Ni layer is exposed. Sample No. In Tables 6 to 11, when a surface elemental analysis is performed on a region other than the inside of the bonding region A, as shown in Table 1, Au is not detected (0.1% or less), and Ni contained in the exposed Ni layer is 90%. %. The sample No. Also in 6 to 11, Fe contained in the base material under the Ni layer was detected in a range of less than 5%.

  Next, the sample no. 1 and sample no. In forming the solder portion in the process of manufacturing the cap of No. 6, it was evaluated whether the solder flows out to the outer peripheral side and the inner peripheral side of the joining region A. Sample No. 1 and No. As for No. 6, before the solder portion forming step, in the respective regions adjacent to the inner peripheral edge and the outer peripheral edge of the solder portion in the annular joint region A, an oxidized region where Ni is oxidized (the first oxidized region on the inner peripheral side). A second dioxide region is provided in an annular shape on the outer peripheral side. After the solder portion forming step, the sample No. 1 and No. The cross section of the sample No. 6 including the bonding region A was observed with an SEM.

  FIG. 1 is an SEM photograph of FIG. The dark gray part in FIG. 12 indicates the substrate. The white portion below the substrate indicates the solder portion. A narrow light gray portion along the outer peripheral edge of the substrate indicates the Ni layer. The broken line is added to indicate the boundary between the base material and the Ni layer. The sample No. 1 is provided with an oxidized region (first oxidized region, second oxidized region). As shown in FIG. In 1, the liquid solder flowed out of the joining region A toward the outside (from the lower surface of the flange portion to the left side surface) on the surface of the Au layer, and the solder portion was also formed outside the joining region A.

  FIG. 6 is an SEM photograph of FIG. The dark gray part in FIG. 13 indicates the substrate. The white portion below the substrate indicates the solder portion. A narrow gray portion along the outer peripheral edge of the substrate indicates the Ni layer. The broken line is added to indicate the boundary between the base material and the Ni layer. The sample No. 6 has an oxidized region (second dioxide region) similar to that of sample 1. As shown in FIG. In No. 6, the liquid solder is applied on the surface of the Ni layer toward the outer peripheral side (from the lower surface of the flange portion to the left side surface) and the inner peripheral side (from the lower surface of the flange portion to the surface of the side plate portion in the cavity of the base material) of the joining region A. The solder portion was formed in the joining region A without remaining in the joining region A without flowing out.

  Next, the sample no. 2 and No. With regard to No. 7, the bonding state at the time of bonding with the ceramic member was evaluated. Sample No. joined to the ceramic member 2 and No. 7 was observed by SEM. Sample No. 2 and No. As for No. 7, an oxidized region (first oxidized region) in which Ni is oxidized is formed in a region (bent portion from the flange portion to the side plate portion of the base material) adjacent to the inner peripheral edge of the solder portion in the annular joint region A. Provided. Note that no oxidized region (second dioxide region) was provided in a region adjacent to the outer peripheral edge of the solder portion in the annular joint region A.

  FIG. 2 shows a state in which the second cap is joined to a ceramic member. In FIG. 14, a white portion indicates a solder portion, a gray portion above the white portion indicates a base material, and a gray portion (including a mottled portion) below the white portion indicates a ceramic member. Note that only a part of the ceramic member is shown. As shown in FIG. In the cap of No. 2, the liquid solder in the cap is outside (from the lower surface of the flange portion to the left side) and inside (from the lower surface of the flange portion) the side plate portion in the cavity of the base material. Then, the solder flowed out onto the surface of the Au layer toward the surface (surface), and a solder portion was also formed outside the bonding region A. In the cavity of the base material, the liquid solder reaches from the surface of the side plate to the lower surface of the bottom plate.

  FIG. 7 shows a state in which the cap 7 is joined to a ceramic member. In FIG. 15, a white portion indicates a solder portion, a gray portion above the white portion indicates a base material, and a gray portion (including a mottled portion) below the white portion indicates a ceramic member. Note that only a part of the ceramic member is shown. As shown in FIG. In the cap of No. 7, in the cap, the liquid solder is provided on the outer peripheral side (from the lower surface of the flange portion to the left side surface) and the inner peripheral side (from the lower surface of the flange portion to the cavity of the base material) in the joining region A provided on the lower surface of the flange portion. (The surface of the side plate portion) and did not flow onto the surface of the Ni layer but remained in the joining region A, and the solder portion was formed in the joining region A.

  Next, the sample Nos. 12-No. The surface roughness was measured at an arbitrary point B (see FIG. 2) on the cavity-side surface of the bottom plate portion of the cap No. 21. Table 2 shows the results. The surface roughness was evaluated based on the maximum height (Rz) specified in JIS B0601. The measuring device used was VK-8710 manufactured by Keyence Corporation. The sample No. Nos. 12 to 21 correspond to the above Nos. It produced similarly to 6-11. Sample No. In Nos. 12 to 21, the etching conditions (such as the composition and temperature of the etching solution, the current density and time of etching, etc.) were adjusted such that the maximum height (Rz) after removing the Au plating layer was 1.0 μm or more. .

  As shown in Table 2, the sample Nos. 12-No. The maximum height (Rz) of the surface of the Ni layer of the cap No. 21 was 1.47 μm to 1.99 μm, and all were 1.0 μm or more. Since the surface of the Ni layer of the cap of this embodiment has an appropriate maximum height (Rz) of 1.0 μm or more, the wettability of the Au—Sn-based liquid solder is low. As described above, the maximum height (Rz) of the surface of the Ni layer is preferably 1.2 μm or more, more preferably 1.4 μm or more, from the viewpoint of further reducing the wettability of the Au—Sn liquid solder. The thickness is desirably 3.0 μm or less from the viewpoint of practical use such as manufacturing efficiency and the like, and desirably 2.5 μm or less from the viewpoint of enhancing practicability.

DESCRIPTION OF SYMBOLS 1 Electronic component accommodation package 2 Ceramic member 10 Hermetic sealing cap 20 Base material 21 Cavity part 22 Flange part 23 Bottom plate part 24 Side plate part 25 Solder part 26 Ni layer 27 First oxidation region 28 Second oxidation region 31 Au layer 40 Solder member A Bonding area B Surface roughness measurement point

Next, the caps of the examples according to the present invention (samples Nos. 6 to 11) and the caps of comparative examples different from the present invention (samples Nos. 1 to 5) were prepared and evaluated. In each sample, the base material was a base material made of an Fe-based alloy formed by a metal plate made of an Fe-Ni-Co-based alloy containing 30% by mass of Ni, and the Ni layer was formed by electrolytic Ni plating. The Ni plating layer was used, and the Au layer was an Au plating layer formed by electrolytic Au plating .

Claims (7)

An airtight sealing cap used for an electronic component housing package including an electronic component housing member for housing an electronic component,
A surface of a substrate having a cavity portion having a cavity formed by a bottom plate portion and a side plate portion, and a flange portion provided in an annular shape so as to surround an opening of the cavity, is covered with a Ni layer,
A joining area for joining to the electronic component housing member is provided in the flange portion,
A solder portion made of Au-Sn based solder is provided in the joining region so as to cover the Ni layer,
A hermetic sealing cap in which the Ni layer is exposed in a region excluding the bonding region.   2. The element according to claim 1, wherein in a surface elemental analysis by energy dispersive X-ray analysis (EDX) of a surface of the base material other than the bonding region, Au is 0.1% by mass or less and Ni is 90% by mass or more. The hermetic sealing cap according to the above.   3. The hermetic sealing cap according to claim 1, wherein a maximum height (Rz) defined by JIS B0601 on a surface of a region of the base material other than the bonding region is 1.0 μm or more. 4. A method for manufacturing a hermetic sealing cap used for an electronic component housing package including an electronic component housing member for housing an electronic component,
The hermetic sealing cap,
A surface of a substrate having a cavity portion having a cavity formed by a bottom plate portion and a side plate portion, and a flange portion provided in an annular shape so as to surround an opening of the cavity, is covered with a Ni layer,
A joining area for joining to the electronic component housing member is provided in the flange portion,
A solder portion made of Au-Sn based solder is provided in the joining region so as to cover the Ni layer,
The Ni layer is exposed in a region excluding the bonding region,
The manufacturing method comprises:
Pressing a metal plate to form an intermediate body including the cavity portion and the flange portion,
A Ni layer forming step of forming the Ni layer on the entire surface of the intermediate;
Forming an Au layer on the entire surface of the Ni layer,
A solder portion forming step of forming the solder portion made of Au-Sn based solder on the surface of the Au layer corresponding to the joining region of the flange portion;
A method of manufacturing a hermetic sealing cap, comprising: an etching step of removing the Au layer by an etching process.   The method for manufacturing a hermetic sealing cap according to claim 4, wherein the etching step is performed using a cyan-based etchant.   In the surface element analysis by energy dispersive X-ray analysis (EDX) of the surface of the substrate except for the bonding region, the etching step is performed so that Au is 0.1% by mass or less and Ni is 90% by mass or more. The hermetic sealing cap according to claim 4 or 5, wherein the sealing is performed.   7. The etching step according to claim 4, wherein the etching step is performed such that a maximum height (Rz) defined by JIS B0601 of a surface of the base material other than the bonding region is 01.0 μm or more. 7. The hermetic sealing cap according to 1.